SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Using Figure 2.1, match the following:
Figure 2.2
Using Figure 2.2, match the following:
MATCHING. Choose the item in column 2 that best matches each item in column 1.
Match the following chemical bonds to the correct description:
13) A bond in which electrons are shared unequally.
14) A bond in which electrons are completely lost or gained by the atoms involved.
15) A bond in which electrons are shared equally.
16) A type of bond important in tying different parts of the same molecule together into a three-dimensional structure.
Match the following particles to the correct description:
17) Negatively charged subatomic particle.
18) Neutral subatomic particle.
19) Smallest particle of an element that retains its properties.
20) Positively charged subatomic particle.
21) Subatomic particle having an AMU (Atomic Mass Unit) of zero.
Match the following:
22) Water.
23) Saline.
24) Dry ice (frozen carbon dioxide).
25) Blood.
Match the following:
26) Can be measured only by its effects on matter.
27) Anything that occupies space and has mass.
28) Although a man who weighs 175 pounds on Earth would be lighter on the moon and heavier on Jupiter, his ________ would not be different.
29) Is a function of, and varies with, gravity.
Match the following:
30) Legs moving the pedals of a bicycle.
31) When the bonds of ATP are broken, energy is released to do cellular work.
32) Energy that travels in waves. Part of the electromagnetic spectrum.
33) Represented by the flow of charged particles along a conductor, or the flow of ions across a membrane.
Match the following:
34) Protein structure achieved when alpha-helical or beta-pleated regions of the polypeptide chain fold upon one another to produce a compact ball-like, or globular, molecule.
35) The sequence of amino acids that form the polypeptide chain.
36) Protein structure represented by alpha-helices and beta-sheets.
37) Two or more polypeptide chains, each with its own tertiary structure.
Mass
Electrical energy
Chemical energy
Radiant energy
Mechanical energy
38) Usually, the first one or two letters of an element's name.
39) Number of protons in an atom.
40) Combined number of protons and neutrons in an atom.
A) Mass number of an element
Atomic number
Atomic symbol
TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false.
41) The atomic number of any atom is equal to the number of electrons in its nucleus and is written as a subscript to the left of its atomic symbol.
42) It is the difference in the R group that makes each amino acid chemically unique.
43) Chemical properties are determined primarily by neutrons.
44) A charged particle is generally called an ion or electrolyte.
45) Isotopes differ from each other only in the number of electrons the atom contains.
46) About 60% to 80% of the volume of most living cells consists of organic compounds. 46)
47) Triglycerides are a poor source of stored energy. 47)
48) Omega-3 fatty acids appear to decrease the risk of heart disease. 48)
49) Glucose is an example of a monosaccharide.
50) Glycogen, the storage form of glucose, is primarily stored in skeletal muscle and liver cells. 50)
51) The lower the pH, the higher the hydrogen ion concentration. 51)
52) The sharing of electrons in covalent bonds makes them stronger than ionic and hydrogen bonds. 52)
53) Hydrogen bonds are too weak to bind atoms together to form molecules, but they do hold different parts of a single large molecule in a specific three-dimensional shape. 53)
54) The fact that no chemical bonding occurs between the components of a mixture is the chief difference between mixtures and compounds. 54)
55) The acidity of a solution reflects the concentration of free hydrogen ions in the solution. 55)
56) A chemical bond is an energy relationship between outer electrons and neighboring atoms. 56)
57) All organic compounds contain carbon except CO2 and CO. 57)
58) A dipeptide can be broken into two amino acids by dehydration synthesis. 58)
59) The pH of body fluids must remain fairly constant for the body to maintain homeostasis. 59)
60) Mixtures are combinations of elements or compounds that are physically blended together but are not bound by chemical bonds. 60)
61) Buffers resist abrupt and large changes in the pH of body fluids by releasing or binding ions. 61)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
62) Which of the following elements is necessary for proper conduction of nerve impulses? A) P B) Fe C) Na D) I
63) The basic structural material of the body consists of ________.
A) carbohydrates B) nucleic acids C) lipids D) proteins
64) In general, the lipids that we refer to as oils at room temperature have ________.
A) long fatty acid chains B) saturated fatty acids
C) a high water content D) unsaturated fatty acids 64)
65) The genetic information is coded in DNA by the ________.
A) regular alteration of sugar and phosphate molecules
B) three-dimensional structure of the double helix
C) arrangement of the histones
D) sequence of the nucleotides
66) Which of the following does NOT characterize proteins?
A) They have both functional and structural roles in the body.
B) They may be denatured or coagulated by heat or acidity.
C) Their function depends on their three-dimensional shape.
D) They appear to be the molecular carriers of coded hereditary information. 66)
67) The single most abundant protein in the body is ________. A) DNA B) collagen C) glucose D) hemoglobin
68) Carbohydrates are stored in the liver and skeletal muscles in the form of ________. A) glycogen B) cholesterol C) glucose D) triglycerides 68)
69) Which of the following does NOT describe enzymes?
A) Some enzymes are purely protein.
B) Enzymes work by raising the energy of activation.
C) Each enzyme is chemically specific.
D) Some enzymes are protein plus a cofactor. 69)
70) Which of the following is a general function for a fibrous protein?
A) catalysis
B) transport
C) structural framework
D) protein management
E) body defense
71) A chemical reaction in which bonds are created is usually associated with ________.
A) degradation
C) the release of energy
72) Salts are always ________.
A) double covalent compounds
C) single covalent compounds
B) the consumption of energy
D) forming a smaller molecule
B) ionic compounds
D) hydrogen bonded
73) The numbers listed represent the number of electrons in the first, second, and third energy levels, respectively. On this basis, which of the following is an unstable or reactive atom?
A) 2, 8, 8 B) 2, 8, 1
74) Which of the following statements is FALSE?
C) 2, 8 D) 2
A) The more hydrogen ions in a solution, the more acidic the solution.
B) The pH of blood is slightly basic.
C) When acids and bases are mixed, they react with each other to form water and a salt.
D) When the hydrogen ion concentration decreases, the hydroxyl ion concentration also decreases.
75) Which of the following is the major positive ion outside cells?
A) potassium B) magnesium C) hydrogen D) sodium
76) Which of the following would be regarded as an organic molecule?
CO2 B) H2O
77) What is a chain of more than 50 amino acids called?
polysaccharide B) protein
NaOH
nucleic acid
CH4
triglyceride
78) What structural level is represented by the sequence of amino acids in a polypeptide chain?
A) primary structure B) secondary structure C) tertiary structure D) quaternary structure
79) Carbohydrates and proteins are built up from their basic building blocks by the ________.
A) removal of a water molecule between each two units
B) addition of a carbon atom between each two units
C) removal of a carbon atom between each two units
D) addition of a water molecule between each two units
80) Which statement about enzymes is FALSE?
A) Most enzymes can catalyze millions of reactions per minute.
B) Enzymes require contact with substrate in order to assume their active form.
C) Enzymes may use coenzymes derived from vitamins or cofactors from metallic elements.
D) Enzymes may be damaged by high temperature.
81) Which of the following statements is FALSE?
A) Chemical reactions progress at a faster rate when the reacting particles are present in higher numbers.
B) Larger particles move faster than smaller ones and thus collide more frequently and more forcefully.
C) Catalysts increase the rate of chemical reactions, sometimes while undergoing reversible changes in shape.
D) Chemical reactions proceed more quickly at higher temperatures.
82) Choose the answer that best describes HCO3.
A) a weak acid
C) a proton donor
B) common in the liver
D) a bicarbonate ion
83) Select which reactions will usually be irreversible regarding chemical equilibrium in human bodies.
A) glucose to CO2 and H2O
B) glucose molecules joined to make glycogen
C) H2O + CO2 to make H2CO3
D) ADP + Pi to make ATP
84) What happens in redox reactions?
A) both decomposition and electron exchange occur
B) the reaction is uniformly reversible
C) the electron acceptor is oxidized
D) the organic substance that loses hydrogen is usually reduced
85) Which type of proteins can function as chemical messengers or as receptors in the plasma membrane?
A) defensive B) enzyme
C) transport D) communication
86) Which of the following does NOT describe uses for the ATP molecule?
A) transport down their concentration gradient
B) chemical work
C) pigment structure
D) mechanical work
87) Select the most correct statement regarding nucleic acids.
A) Three forms exist: DNA, RNA, and tDNA.
B) tDNA is considered a "molecular slave" of DNA during protein synthesis.
C) DNA is a long, double-stranded molecule made up of A, T, G, and C bases.
D) RNA is a long, single-stranded molecule made up of the bases A, T, G, and C.
88) Which of the following is an example of a suspension?
A) blood B) cytosol C) rubbing alcohol D) salt water 88)
89) If the atomic mass of an element is 14 and the atomic number is 6, which of the following would describe this element?
A) ion B) isotope
C) neutral D) atom
90) The four elements that make up about 96% of body weight are ________.
A) sodium, potassium, hydrogen, oxygen B) carbon, oxygen, phosphorus, calcium
C) nitrogen, hydrogen, calcium, sodium
D) carbon, oxygen, hydrogen, nitrogen
91) ________ is fat soluble, produced in the skin on exposure to UV radiation, and necessary for normal bone growth and function.
A) Vitamin A B) Vitamin K
C) Cortisol D) Vitamin D
92) You notice that you cannot read your book through a test tube of patient fluid held against the print, making it so blurred as to be unreadable. There is no precipitant in the bottom of the beaker, though it has been sitting for several days in a rack. What type of liquid is this?
A) solution B) suspension
C) mixture D) colloid
93) Atom X has 17 protons. How many electrons are in its valence shell (outermost energy level)?
A) 7 B) 3 C) 5 D) 10
94) A high fever causes an enzyme to lose its three-dimensional structure and function. Which bonds are broken when a protein denatures?
A) hydrogen bonds
C) ionic bonds
B) polar covalent bonds
D) non-polar covalent bonds
95) If atom X has an atomic number of 74 it would have which of the following?
A) 74 protons
C) 37 protons and 37 neutrons
96) What does the formula C6H12O6 mean?
A) The molecular weight is 24.
B) 37 protons and 37 electrons
D) 37 electrons
B) There are 6 calcium, 12 hydrogen, and 6 oxygen atoms.
C) There are 6 carbon, 12 hydrogen, and 6 oxygen atoms.
D) The substance is a colloid.
97) An atom with 3 electrons in its outermost (valence) shell may have a total of ________ electrons altogether.
13 B) 3
98) Which of the following is a neutralization reaction?
A) NH3 + H+ → NH4+2
C) NaOH → Na+ + OH-
99) The chemical symbol O=O means ________.
A) zero equals zero
B) the atoms are double bonded
C) this is an ionic bond with two shared electrons
17 D) 8
B) HCl + NaOH → NaCl + H2O
D) HCl → H+ + Cl-
D) both atoms are bonded and have zero electrons in the outer orbit
100) What is a cation?
A) an atom that shares its valence electrons
B) a molecule that has both positive and negative charges
C) an atom that gains one or more electrons and acquires a net negative charge
D) an atom that loses one or more electrons and acquires a net positive charge
101) What does CH4 mean?
A) There is one carbon and four hydrogen atoms.
B) This is an inorganic molecule.
C) There are four carbon and four hydrogen atoms.
D) This was involved in a redox reaction.
102) Amino acids joining together to make a peptide is a good example of a(n) ________ reaction.
A) decomposition B) synthesis C) reversible D) exchange
103) Which of the following is NOT considered a factor in influencing a reaction rate?
A) time
C) particle size
B) concentration of reactants
D) temperature
104) Which property of water is demonstrated when we sweat?
A) reactivity
B) cushioning
C) high heat capacity
D) high heat of vaporization
E) polar solvent properties
105) Starch is a ________.
A) monosaccharide
C) triglyceride
B) polysaccharide
D) disaccharide
106) What is the ratio of fatty acids to glycerol in triglycerides (neutral fats)?
A) 2:1 B) 3:1
107) In a DNA molecule, the phosphate serves ________.
A) as nucleotides
C) as a code
C) 1:1 D) 4:1
B) to bind the sugars to their bases
D) to hold the molecular backbone together
108) When frying an egg, the protein albumin denatures and maintains only its ________ structure.
A) primary B) quaternary C) tertiary D) secondary
109) Which of the following is chemically inert (unreactive)?
A) sodium (atomic number 11)
C) oxygen (atomic number 8)
B) neon (atomic number 10)
D) carbon (atomic number 6) 109)
110) An atom with an atomic number of 10 and a mass number of 24 would have ________.
A) 24 protons B) 14 electrons C) 10 neutrons D) 14 neutrons 110)
111) When DNA is replicated, it is necessary for the two strands to "unzip" temporarily. Choose which bonding type is most appropriate for holding the strands together in this way.
A) polar covalent bonding
C) ionic bonding
B) hydrogen bonding
D) non-polar covalent bonding
112) Lithium has an atomic number of 3. How many electrons are there in the outermost (valence) shell?
A) one B) two C) three D) zero 112)
113) ATP → ADP + Pi is an example of a(n) ________ reaction.
A) decomposition B) exchange C) reversible D) synthesis 113)
114) An acid with a pH of 6 has ________ hydrogen ions than pure water.
A) 10-fold more B) 100-fold more C) 100-fold fewer D) 10-fold fewer
115) A patient is hyperventilating. The "blowing off" of excessive carbon dioxide causes a decrease in blood H+ concentration. How can the carbonic acid-bicarbonate buffer system function to correct this imbalance?
CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3-
A) H2CO3 dissociates to form more H+ and lower pH
B) HCO3- binds with H+ to form H2CO3 and raise pH
C) H2CO3 dissociates to form more H+ and raise pH
D) HCO3- binds with H+ to form H2CO3 and lower pH
116) Forming glycogen as energy storage in the liver is an example of ________. A) catabolism B) exergonic C) oxidation D) anabolism
117) Salivary amylase is an enzyme produced by the salivary glands that breaks down carbohydrates. What will happen to this enzyme as it follows the food into the stomach where the pH drops to 2.5?
A) The enzyme will continue to function as it remains unchanged in chemical reactions.
B) The enzyme will denature and become inactive.
C) The enzyme will assume an alternate form and catalyze additional reactions.
D) The enzyme will denature but retain its function.
118) With a family history of cardiovascular disease, which toast spread would be considered the most "heart healthy"?
A) olive oil
C) margarine containing trans fats
119) Which of the following is incorrectly matched?
A) nucleotide; nucleic acid
C) eicosanoid; triglyceride
B) lard (pig fat)
D) butter containing butterfat
B) monosaccharide; carbohydrate
D) amino acid; protein 119)
120) Starch is the stored carbohydrate in plants, while ________ is the stored carbohydrate in animals. A) triglyceride B) glucose C) glycogen D) cellulose 120)
121) How many phosphates would ADP have attached to it?
A) three B) one C) none D) two
122) Tendons are strong, rope-like structures that connect skeletal muscle to bone. Which of the following proteins would provide strength to a tendon?
A) actin
C) albumin
B) collagen
D) molecular chaperone
123) Phospholipids make up most of the lipid part of the cell membrane. Since water exists on both the outside and inside of a cell, which of the following phospholipid arrangements makes the most sense?
A) two back-to-back phospholipid layers with the non-polar tails facing out on both sides
B) a single layer of phospholipids with the polar heads facing outside the cell
C) a single layer of phospholipids with the polar heads facing inside the cell
D) two back-to-back phospholipid layers with the polar heads facing out on both sides
124) What type of chemical bond can form between an atom with 11 protons and an atom with 17 protons?
A) polar covalent
C) hydrogen
B) ionic
D) non-polar covalent
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
125) What happens when globular proteins are denatured? 125)
126) Explain the difference between potential and kinetic energy. 126)
127) How can phospholipids form a film when mixed in water? 127)
128) What properties does water have that make it a very versatile fluid? 128)
129) What advantages does ATP have in being the energy currency molecule? 129)
130) Explain why water is considered to have partial charges even though it is sharing electrons in a polar covalent bond. 130)
131) When a set of electrodes connected to a light bulb is placed in a solution of dextrose and a current is applied, the light bulb does not light up. When the same unit is placed in HCl, it does. Why?
132) Describe the factors that affect chemical reaction rates. 132)
133) Protons and electrons exist in every atom nucleus except hydrogen. Is this statement true or false and why? 133)
134) A chemical bond never occurs between components of a mixture. Discuss this. 134)
135) All chemical reactions are theoretically reversible. Comment on this statement. 135)
136) What is the major difference between polar and nonpolar covalent bonds? 136)
137) An amino acid may act as a proton acceptor or donor. Explain. 137)
138) Name at least four things you know about enzymes. 138)
139) In the compound H2CO3, what do the numbers 2 and 3 represent? 139)
140) Are all chemical reactions reversible? If not, why aren't they all reversible? 140)
141) If all protons, electrons, and neutrons are alike, regardless of the atom considered, what determines the unique properties of each element? 141)
ESSAY. Write your answer in the space provided or on a separate sheet of paper.
142) Mrs. Mulligan goes to her dentist and, after having a couple of cavities filled, her dentist strongly suggests that she reduce her intake of sodas and increase her intake of calcium phosphates in the foods she eats. Why?
143) Although his cholesterol levels were not high, Mr. Martinez read that cholesterol was bad for his health, so he eliminated all foods and food products containing this molecule. He later found that his cholesterol level dropped only 20%. Why did it not drop more?
144) How can DNA be used to "fingerprint" a suspect in a crime?
145) Why is it possible for us to drink a solution that contains a mixture of equal concentration of a strong acid and a strong base, either of which, separately, would be very caustic?
146) A 65-year-old patient came to the emergency room with complaints of severe heartburn unrelieved by taking a "large handful" of antacids. Would you expect the pH to be high or low? Explain why.
147) A 22-year-old female college student is stressed out due to final exams and begins to hyperventilate. This means she is exhaling too much carbon dioxide. As a result, the pH of the blood will become too basic creating a homeostatic imbalance. Her friend hands her a paper bag and instructs her to inhale and exhale into the bag. Breathing in the bag helps to replace the lost carbon dioxide lowering the pH back to normal levels. Which buffer system in the body will be involved in this reaction?
148) Brenda is a 26-year-old female who is being discharged from the hospital after a vaginal delivery of an 8-pound healthy infant. Brenda is instructed by the nurse to eat a diet high in fiber and to drink 8 glasses of water per day to prevent constipation. Explain the role of fiber and water to promote defecation.
Answer Key
Testname: UNTITLED49
1) D 2) B
3) E
4) C
5) A
6) C
7) B
8) B
9) D
10) E
11) C
12) A
13) A
14) D 15) C
16) B
17) B
18) D
19) A
20) C
21) B
22) B
23) A
24) B
25) C
26) D
27) B
28) A
29) C
30) D
31) B
32) C
33) A
34) D
35) B
36) C
37) A
38) C
39) B
40) A
41) FALSE
42) TRUE
43) FALSE
44) TRUE
45) FALSE
46) FALSE
47) FALSE
48) TRUE
49) TRUE
50) TRUE
Answer Key
Testname: UNTITLED49
51) TRUE 52) TRUE 53) TRUE 54) TRUE
55) TRUE 56) TRUE
57) TRUE 58) FALSE 59) TRUE 60) TRUE 61) TRUE 62) C 63) D 64) D 65) D
66) D
67) B
68) A 69) B
70) C
71) B
72) B 73) B 74) D
75) D 76) D
77) B
78) A
79) A 80) B
81) B
82) D 83) A 84) A 85) D
86) C
87) C
88) A 89) B
90) D 91) D
92) D
93) A 94) A 95) A 96) C
97) A 98) B 99) B
100) D
101) A
102) B
103) A
104) D
105) B
106) B
107) D
108) A
109) B
110) D
111) B
112) A
113) A
114) A
115) A
116) D
117) B
118) A
119) C
120) C
121) D
122) B
123) D
124) B
125) The active sites are destroyed.
126) Potential energy is inactive stored energy that has potential to do work. Kinetic energy is energy in action.
127) Phospholipids have both polar and nonpolar ends. The polar end interacts with water, leaving the nonpolar end oriented in the opposite direction.
128) High heat capacity, high heat of vaporization, polar solvent properties, reactivity, and cushioning.
129) Its energy is easy to capture and store; it releases just the right amount of energy for the cell's needs so it is protected from excessive energy release. A universal energy currency is efficient because a single system can be used by all the cells in the body.
130) Due to the electronegativity of oxygen, it pulls the shared electron more strongly than the hydrogen. As a result, the oxygen acquires a partial negative charge, and the hydrogens acquire a partial positive charge.
131) HCl ionizes to form current-conducting electrolytes. Dextrose does not ionize, and therefore does not conduct current.
132) Temperature increases kinetic energy and therefore the force of molecular collisions. Particle size: smaller particles move faster at the same temperature and therefore collide more frequently; also, smaller particles have more surface area given the same concentration of reactants. Concentration: the higher the concentration, the greater the chance of particles colliding. Catalysts increase the rate of the reaction at a given temperature. Enzymes are biological catalysts.
133) False. Hydrogen has one proton and one electron. It is the neutron, not the electron that can coexist in the nucleus and that hydrogen does not have.
134) Mixtures come in three forms–solutions, colloids, and suspensions. Components of these mixtures always retain their original makeup and can be separated into their individual components; therefore, no chemical bonding has taken place.
135) It is possible to reverse any reaction if the products are still present. Those that are only slightly exergonic are easily reversible. Some would require an enormous amount of energy to reverse. In the simple reaction Na + Cl → NaCl the amount of energy it takes to reverse table salt to chlorine gas and sodium metal is enormous. When glucose is oxidized the energy goes into bonds of ATP molecules which are then spent and thus the energy is not available to reform glucose.
136) Polar bonds have an unequal sharing of electrons resulting in a slight negative charge at one end of the molecule and a slight positive charge at the other end. Nonpolar bonds have an equal sharing of electrons, resulting in a balanced charge among the atoms.
137) Amino acids have two components–a base group (proton acceptor) and an organic acid part (a proton donor). Some have additional base or acid groups on the ends of their R groups as well.
138) 1. Most are proteins.
2. They have specific binding sites for specific substrates.
3. They lower the activation barrier for a specific reaction.
4. The names often end in "Suffix: -ase."
5. They can be denatured.
6. They can be used again and again.
139) The 2 indicates that there are two hydrogen atoms in the compound and the 3 indicates that there are three oxygen atoms in the compound.
140) All chemical reactions are theoretically reversible, but only if the products are not consumed and enough energy is available for the reaction.
141) Atoms of different elements are composed of different numbers of protons, electrons, and neutrons.
142) Sodas are strong acids that can reduce bone and tooth salts. Calcium phosphate makes teeth hard and therefore more resistant to tooth decay.
143) Cholesterol is produced by the liver, in addition to being ingested in foods.
144) The DNA of a person is unique to that individual. By obtaining the DNA from nucleated cells from the crime scene (e.g., blood, semen, other body tissues), enzymes may be used to break up the DNA into fragments. Because nearly everyone's DNA is different, it also breaks up into fragments differently. When the fragments are separated, they form patterns even more unique than fingerprint patterns. A match of suspect and crime scene DNA is strong evidence.
145) When an acid and base of equal strength are mixed, they undergo a displacement (neutralization) reaction to form water and a salt.
146) You would expect a high pH. Taking antacids will neutralize the acidic stomach. Taking a "handful" of antacids can cause an alkaloid state. Certain drugs, such as corticosteroids and antacids that contain baking soda, will lead to metabolic alkalosis.
147) The bicarbonate buffer system is going to be involved in this situation. In this buffer system, the weak acid is carbonic acid, which is formed from the reaction between carbon dioxide and water. The body responds to an increase in blood pH by shifting the equation to the left, causing carbonic acid to dissociate into bicarbonate and protons. These protons will bring the rising pH back to a normal level.
148) Cellulose is a polysaccharide found in all plant products that adds bulk to the diet to promote feces through the colon. Water acts as a lubricating liquid within the colon, which eases feces through the bowel.